Eskisehir Technical University

Debris flows are a significant geohazard in the semi-arid mountain belts of southwestern Türkiye, where short-duration, high-intensity rainfall frequently triggers rapid sediment mobilization, generating destructive debris-flow hazards that threaten settlements, transportation corridors, and agricultural land. The catastrophic 6-7 August 2018 debris-flow event, reported to have caused severe damage to agricultural fields, livestock, and road infrastructure (in both two villages, one day apart) together with more recent rainfall-triggered events in the area, highlights the vulnerability of the region; since these basins drain into the Elmalı polye, a critical agricultural hub, assessing debris-flow susceptibility is essential for future risk mitigation. This study presents a regional debris-flow susceptibility assessment for the Elmalı Basin (Western Taurus Mountains) in Antalya, Türkiye. Using a 5m resolution DEM, NDVI-based vegetation change analyses, topographic thresholds (slope, curvature, flow accumulation), and lithological data, potential source areas were identified, and runout paths were modeled with the empirical Flow-R approach. Model calibration was supported by geomorphic evidence of the 2018 event, and NDVI difference maps provided an effective tool for evaluating the accuracy of runout angle calculations. The results highlight several channels where steep, concave slopes coincide with high-susceptibility zones, indicating that certain settlements and agricultural fields lie within potential impact zones.

The rapid growth of esports has led to increasing participation among middle and late adolescents, raising the need for theoretically grounded and psychometrically sound instruments to assess adolescents’ orientation toward esports. The purpose of this study is to develop and validate the Esports Orientation Tendency Scale (ESOTS), a multidimensional instrument designed to assess adolescents’ orientation toward esports as a technology-mediated leisure tendency. Following established scale development guidelines, an eight-step procedure was employed, including theoretical framework development, item pool generation, expert review, exploratory factor analysis (EFA), confirmatory factor analysis (CFA), reliability assessment, and the evaluation of criterion-related and nomological validity. Data were collected from three independent adolescent samples (N = 829): Sample 1 (n = 300) was used for EFA, Sample 2 (n = 400) for CFA, and Sample 3 (n = 129) for nomological validity testing and supplementary structural (path) modeling and analyzed using EFA, CFA, and structural modeling techniques. The final version of the ESOTS consists of 55 items across six dimensions: Digital Gaming Passion, Leisure Time Utilization, Ease of Access to Esports, Financial Gain, Absence of Demographic Barriers, and Popularity. Results supported the six-factor structure and demonstrated satisfactory model fit, strong internal consistency, and adequate convergent and discriminant validity. Nomological validity analyses indicated that esports orientation is strongly associated with technology acceptance constructs and gaming disorder symptoms, while remaining unrelated to general psychological well-being and academic performance. Overall, the findings indicate that the ESOTS is a reliable and valid instrument for assessing adolescents’ orientation toward esports. The scale provides a nuanced framework for examining esports engagement as a multidimensional orientation and may be useful for research and applied settings aiming to better understand patterns of esports participation and potential risk-related outcomes under specific conditions.

Abstract Ductile irons (spheroidal graphite cast irons, SGI) are widely used in automotive and energy systems due to their high strength, ductility, and excellent machinability. The casting quality of these alloys largely depends on the flow and filling behavior of the molten metal, namely its fluidity. In this study, the effects of pouring temperature, filling time, and metallurgical quality on the fluidity of GGG40 ductile iron were investigated through both experimental and numerical approaches. Experimental trials were conducted at pouring temperatures of 1350 °C, 1400 °C, and 1450 °C; metallurgical quality levels of 10%, 50%, and 90%; and filling times of 5 s and 10 s. The fluidity lengths were measured and statistically evaluated. The results revealed that increasing the pouring temperature and metallurgical quality significantly improved fluidity, while shorter filling times allowed the molten metal to travel longer distances before solidification. Modeling studies performed using a commercial casting simulation software showed strong correlation with the experimental data. Microstructural examinations indicated that higher pouring temperatures and improved metallurgical quality led to a more homogeneous distribution of graphite nodules and an increased ferrite fraction in the matrix. The findings provide valuable insights into the influence of process parameters on the fluidity behavior of ductile iron and offer critical design data for enhancing casting quality and productivity in industrial foundry applications.

Abstract This study employed an innovative electrocoagulation method to treat landfill leachate, utilizing uniquely designed aluminum electrodes. The investigation focused on the effects of various parameters on treatment efficiency, including initial pH, current density, NaCl concentration, and stirring rate. Results demonstrated that the initial COD concentration of 9600 mg/L was reduced to 282 mg/L at a pH of 5, 40 mA/cm 2 , 0.1 M NaCl concentration, and stirring rate of 60 rpm with the removal efficiency of 97%, meeting direct discharge limits. Additionally, successful removal of phosphorus and nitrogen was achieved, underscoring the comprehensive treatment capabilities of electrocoagulation. Furthermore, electrocoagulation sludge was repurposed for geopolymer production, highlighting the potential for sustainable waste management practices. These findings offer valuable insights for optimizing landfill leachate treatment strategies while promoting environmental sustainability and presenting an excellent opportunity for industrial symbiosis. Highlights An innovative electrocoagulation method was employed for the treatment of landfill leachate, utilizing uniquely designed aluminum electrodes. Successful removal of COD, phosphorus, and nitrogen was a noteworthy achievement that meets the criteria for direct discharge into water bodies. Treatment efficiency was optimized by examining the effects of parameters such as initial pH, current density, NaCl concentration, and stirring rate. The utilization of electrocoagulation sludge as raw material for geopolymer production represents a sustainable approach to waste management and resource utilization.

• Optimized concrete mix design using recycled coarse aggregates through DNN and IGWO. • Multi-objective optimization framework reveals trade-offs between density and ultrasonic pulse velocity. • Innovative use of machine learning for modeling water content, density, and UPV in recycled aggregate concrete. • Hybrid approach of Grey Wolf Optimizer and Deep Neural Network achieves superior predictive accuracy. • Validated models offer a sustainable framework for concrete mix design in eco-friendly construction. This study presents a thorough methodology for forecasting and enhancing the essential performance characteristics of concrete with Recycled Coarse Aggregates (RCA), including water content (Wt), density, and Ultrasonic Pulse Velocity (UPV). The attributes are represented as functions of cement content (300–400 kg/m³), RCA percentage (0–100 %), and slump (5–12 ± 1 cm). An experimental database was created using a three-factor, three-level design, followed by exploratory analysis using correlation matrices and three-dimensional response surface plots to identify significant input-output associations. Various modeling techniques, such as Response Surface Methodology (RSM), Decision Tree (DT), K-Nearest Neighbors (KNN), Support Vector Machine (SVM), and a Deep Neural Network (DNN) enhanced by the Improved Grey Wolf Optimizer (IGWO), were assessed. The accuracy of the model was meticulously evaluated by 4-fold cross-validation, Taylor diagrams, and radar plots, demonstrating that the DNN-IGWO hybrid surpassed all other models, achieving the minimal prediction errors and the maximal correlation coefficient (R 2 ) values for all target responses. The validated models were later employed as surrogates inside a multi-objective optimization framework employing the Multi-Objective Grey Wolf Optimizer (MOGWO). The optimization produced well-distributed Pareto fronts, emphasizing the intrinsic trade-off between density and UPV. The resultant "knee" solutions identify specific concrete compositions that optimize UPV (3.6–3.7) while ensuring a high density (≥2400 kg/m³) and moderate water content. This study provides a scientifically robust, data-driven paradigm for the sustainable design of concrete mixtures, facilitating the appropriate incorporation of recycled aggregates while enhancing material qualities.

While governance theories are well-established, their operational application to transboundary serial cultural heritage remains minimally explored, particularly regarding comparative methodologies for evaluating cooperation maturity. This study addresses this gap by investigating the relationships among institutional models, cooperation mechanisms, and management maturity levels across different countries. The research utilizes a qualitative comparative analysis of the management plans of fifteen transboundary serial cultural heritage sites on the UNESCO World Heritage List. Findings show that governance is not limited to the functioning of legal and administrative structures, but is also shaped by trust among stakeholders, knowledge exchange, and participant processes. Four main governance models were identified: institutionalized multinational networks, federal–modular structures, bilateral–local cooperation, and community-led collaboration. In parallel, the developed Corporate Governance and Maturity Positioning Map reveals that the sites fall along six distinct levels, ranging from basic communication to sustained governance networks. The study argues that the primary factor determining management effectiveness is the intensity of interaction and continuity of coordination rather than institutional capacity. Overall, the findings suggest that cultural heritage governance should be understood as a multi-layered, learning-based, and diplomatic process.

The increasing burden of infectious diseases and antimicrobial resistance underscores the urgent need for alternatives to conventional therapeutics. Although Eucalyptus essential oils (EOs) are well recognized for their broad-spectrum antimicrobial and antibiofilm properties, their relatively high volatility and limited physicochemical stability restrict their practical applications. In this study, a systematic, design-driven comparative approach was employed to develop nanoemulsions containing Eucalyptus globulus, E. citriodora, and E. radiata EOs, with the aim of improving their stability and biological efficacy. Initially, gas chromatography-mass spectrometry was performed to identify species-specific chemotypes, which guided rational formulation design. A Box-Behnken design enabled the precise optimization of critical colloidal parameters, resulting in nanoemulsions with droplet sizes below 200 nm, polydispersity indices below 0.3, and ζ-potentials of approximately -22 mV. Comprehensive structural characterization by Fourier transform infrared spectroscopy and scanning electron microscopy, together with stress testing, confirmed the robust physical stability of the formulations. In-vitro antimicrobial evaluations against Staphylococcus aureus, Enterococcus faecalis, and Klebsiella pneumoniae revealed up to a 4-fold enhancement in antimicrobial activity and up to 80% inhibition of biofilm compared to the corresponding unformulated essential oils. The enhancements are most likely attributable to enhanced dispersion, increased interaction with greater microbial interfaces, and nanoscale stabilization of volatile bioactive constituents. Collectively, the optimized Eucalyptus nanoemulsions constitute reproducible, chemically well-defined nanocarrier systems with markedly improved antibacterial and antibiofilm performance, highlighting their promise as next-generation delivery systems for phytopharmaceutical applications. Further comprehensive biological and toxicological investigations are required to support the safe and effective translation of essential oil-containing nanocapsulations into practical use.